Generally speaking, a photosensitive element of a camera can be implemented by a complementary metal-oxide semiconductor (CMOS) or a charge coupled device (CCD). Nevertheless, when the complementary metal-oxide semiconductor is applied, only a row of photosensitive elements are exposed at each time point. Therefore, when a camera or an object to be captured moves during image capturing, a so-called rolling shutter effect is generated.
FIG. 1 is a schematic diagram illustrating a rolling shutter effect.
As shown in FIG. 1, a camera 110 is applied to capture an object 120. Ideally, in the captured image, the object 120 should be in an upright position (such as an object 130). Here, it is assumed that a time for the camera 110 to capture an image is S. During the process of capturing the object 120, the location of the camera 110 at a time point nS is not the same as the location of the camera 110 at a time point (n+1)S. As such, in the captured image 140, the object 150 is actually in a tilted position. This is because the camera 110l captures the upper half of the object 120 at the time point nS, and while the camera 110 is going to capture the bottom half of the object 120, the location of the camera 110 has already been changed. In other words, if the object to be captured moves rapidly, there will be one horizontal translation for the pixel values obtained by the photosensitive element on each row. Thus, how to correct the rolling shutter effect generated during image capturing has become one of the concern topics to people having ordinary skill in the pertinent field.